Organic light emitting diodes (OLEDs) have advantages such as self-light emission, high brightness and contrast, light weight, low power consumption, and rapid reaction time. OLED-related components in image display systems may be driven using passive or active matrix techniques. Active matrix OLED displays may include, for example, amorphous silicon (a-Si) thin film transistors (TFTs) or low temperature poly silicon (LTPS) TFTs.
a-Si TFTs have advantages but may also have inconsistent performance properties such as floating state issues that adversely affect threshold voltage and element mobility over time. These issues may result in mura phenomena problems including non-uniform display appearances such as dark spots or poorly contrasted areas. LTPS TFTs also have advantages such as a small size that allows for an increased pixel aperture ratio. They can also be manufactured on a glass substrate at the same time as a pixel driving circuit located on a display panel periphery, thereby reducing the number of wires needed in the display. This manufacturing technique may enhance reliability and decrease manufacturing costs for OLED display panels. However, LPTS TFTs also have inconsistent performance properties that can result in mura phenomena difficulties.
To address mura phenomena issues, one may store threshold voltage and pixel mobility values collected when displaying each gray level in each pixel during, for example, the manufacturing process. The threshold voltage and mobility values are then input with pixel data for each pixel to provide voltage compensation that counters mura phenomenon issues and allows each pixel to display precise desired colors. However, storing such large amounts of data requires large memory capacity.